1. Field of the Invention
This invention relates to automatic actuators commonly used in conjunction with inflators for inflating articles such as personal flotation devices, rafts, buoys and emergency signaling equipment. More particularly, this invention relates to squib powered, water activated actuators which are automatically actuated upon immersion in water or other fluid.
2. Description of the Background Art
Presently, there exist many types of inflators designed to inflate inflatable articles such as personal flotation devices (life vests, rings and horseshoes), life rafts, and emergency signaling equipment. These inflators typically comprise a body for receiving the neck of a cartridge of compressed gas such as carbon dioxide. A reciprocating pierce pin is disposed within the body for piercing the frangible seal of the cartridge to permit the compressed gas therein to flow into a manifold in the body and then into the device to be inflated. Typically, a manually movable firing lever is operatively connected to the piercing pin such that the piercing pin pierces the frangible seal of the cartridge upon jerking of a ball lanyard. U.S. Pat. No. 3,809,288, the disclosure of which is hereby incorporated by reference herein, illustrates one particular embodiment of a manual inflator.
While these manual inflators work suitably well, it was quickly learned that in an emergency situation, the person needing the assistance of the inflatable device, such as a downed aviator, injured person, or a man overboard, would fail or be unable to manually actuate the inflator. Accordingly, it was realized that a means should be provided for automatically actuating the inflator in such an emergency situation.
In response to this need, water activated automatic inflators have been developed which, when exposed to a fluid such as water, automatically actuate the piercing pin of the inflator causing inflation of the inflatable device.
One type of water activated automatic inflators comprise a water activated trigger assembly including a water dissolvable element which retains a spring-loaded actuator pin in a cocked position in alignment with the pierce pin, either directly or indirectly by means of an intermediate transfer pin. Upon exposure to water, the element dissolves allowing firing of the cocked actuator pin. The actuator pin then strikes the pierce pin to fracture the seal of the cartridge thereby allowing the gas contained therein to flow into the inflatable device to inflate the same. U.S. Pat. Nos. 3,997,079, 4,223,805 4,267,944, 4,260,075 and 4,627,823 the disclosures of each of which are hereby incorporated by reference herein, illustrate several examples of water activated automatic inflators.
While the above automatic inflators work quite well to automatically inflate the inflatable device in the event of an emergency situation, one major disadvantage to these automatic inflators is their tendency to self-actuate while stored for subsequent exigent use. Specifically, it is quite common for the automatic inflator to be stored in a highly humid environment such as on a ship or a boat. Over a period of time, the moisture contained within the humid air is absorbed by the water dissolvable element to such a degree that the element is weakened, particularly since the element is continually subjected to the force of the actuator spring. As the element gradually weakens, the strength of the element eventually becomes insufficient to retain the spring-loaded actuator pin in the cocked position. When the element collapses under the force of the compressed spring of the actuator pin, the actuator pin strikes the piercing pin causing premature and unintentional inflation of the inflatable device.
The problem of premature and unintentional actuation of the automatic inflator is so acute that it is not uncommon for a weakened water destructible or dissolvable element to be replaced with a new element on a periodic basis pursuant to a regularly scheduled maintenance plan. In this regard, it is noted that each of the prior art water activated automatic inflators disclosed in the above referenced patents teach a structure which may easily be disassembled to facilitate removal of a weakened element and the installation of a new one. Indeed, U.S. Pat. No. 4,627,823 discloses a safety-latched automatic actuator designed to relieve the pressure exerted on the water dissolvable element until such time as an emergency situation exists.
Another type of water activated automatic inflators comprise a water activated, squib powered inflator. As the term is commonly used, a squib is a self-contained explosive charge. Upon actuation by electric current, the explosive charge explodes and actuates the inflator. U.S. Pat. Nos. 3,059,814, 3,091,782, 3,426,942, 3,579,964, 3,702,014, 3,757,371, 3,910,457, 4,382,231, 4,436,159 and 4,513,248, the disclosures of each of which are incorporated by reference herein, illustrate several examples of water activated squib-powered inflators.
Unfortunately, many designs of the water activated squib powered inflators do not provide for replacement of the squib after firing, thereby necessitating the return of the inflator to the factory for recharging. Likewise, it is important to conveniently replace the batteries that power the squib so that a periodic maintenance program can be implemented. Finally, it is important to protect the water sensing electrodes and associated electronics from damage in the event the inflator is dropped or otherwise abused, without compromising the water flow in and around the electrodes when the inflator is exposed to water and requires immediate actuation. In addition to protecting the electrodes, it is usually desirable to be able to quickly replace the electrodes and associated electronics in the event of suspected or actual damage or inoperability of the same.
Therefore, it is an object of this invention to provide an apparatus which overcomes the aforementioned inadequacies of the prior art devices and provides an improvement which is a significant contribution to the advancement of the water-activated, squib-powered, inflator art.
Another object of this invention is to provide a water-activated squib-powered inflator for inflating inflatable devices which allows quick and easy replacement of the squib after firing or as otherwise desired.
Another object of this invention is to provide a water-activated squib-powered inflator which allows the quick and easy replacement of the batteries that power the squib and associated electronics.
Another object of this invention is to provide a water-activated squib-powered inflator having water sensing electrodes which are protected from damage in the event the inflator is dropped or otherwise abused while still permitting rapid flow of water in and around the electrodes to sense the same when the inflator is exposed to water.
Another object of this invention is to provide a water-activated, squib-powered inflator in which the water sensing electrodes and associated electronics may be quickly and easily replaced in the event of suspected or actual damage or as otherwise desired.
The foregoing has outlined some of the more pertinent objects of the invention. These objects should be construed to be merely illustrative of some of the more prominent features and applications of the intended invention. Many other beneficial results can be obtained by applying the disclosed invention in a different manner or modifying the invention within the scope of the disclosure. Accordingly, other objects and a fuller understanding of the invention may be had by referring to the summary of the invention and the detailed description of the preferred embodiment in addition to the scope of the invention defined by the claims taken in conjunction with the accompanying drawings.